Wikipedia really nicely describes the start of the film...The film begins in medias res with Dalton Russell (Clive Owen) narrating his plight in the confines of an undisclosed cell, musing about the difference between a cell and a prison. Shortly afterwards, he begins in narration to describe the "perfect" plan for a bank robbery.The robbery begins in flashback as a group of robbers, dressed as painters and utilizing aliases under variants of the name "Steve," enter the bank, disable the security cameras, and take control of the bank. All customers and bank employees are herded into the basement, where they are forced to give up their keys and cell phones and change into painter uniforms and face masks identical to those of the robbers. They then lock the hostages into several rooms, periodically rotating them and introducing themselves among the hostages at various points.Meanwhile, the police arrive and surround the bank.